Improvement in photography on wood



UNITED STATES PATENT ()EEI E.

CHARLES B. BOYLE, OF ALBANY, NEW YORK.

IMPROVEMENT IN PHOTOGRAPHY ON WOOD.

Specification forming part of Letters Patent No. 22,852, dated February8, 1859.

To all whom it may concern:

Be it known that I, CHARLES B. BOYLE, of Albany, in the county of Albanyand State of New York, have invented a new and useful Process of TakingPhotographic Pictures upon Wood; and I hereby declare the following tobe a full and exact description of the same.

In the endeavors which have been made to employ the photographic art inthe preparation of blocks for the wood-engraver great difficulty hasbeen experienced from the sinking of the sensitive solution into thesubstance of the wood beyond the reach of the fixing-solution. Blocksprinted in this manner must be engraved under an artificial light, orthe picture is destroyed before the completion of the work. To obviatethis difficulty the. silver solution has been applied to the blockdirectly in the form of a chloride, which, when dry, pre-' sented asensitive surface, but lacking sufficient adherence to the wood to admitof its being successfully employed for the purposes of the engraver. Themost common method, however, has been to blacken the block and afterwardcoat it with a film of collodion, albumen, gelatine, wax, orothersubstance similar to those employed to form a sensitive surface oninorganic substances-such as metal stanceof the wood itself, while thesensitive solution is prevented from penetrating beyond the reach of thefixing-solution afterward applied second, in a method of treatment whichadmits of the subsequent removal from the wood of all gelatinous orviscid matter without injury to the picture.

The process is as follows: I take the white of an egg, mix it with abouthalt its volume of water, and beat the whole into a white froth. I then,with a piece of canton-flannel or a stiff brush, carefully moisten theface of the block with this fluid and allow it to sink in and dry byspontaneous evaporation. It is then ready for solution N o. 2, which Imakeby dissolving thirty grains of Russian isinglass and two grains ofchloride of sodium in one ounce of warm water. When the solution iscompleted, and while yet warm, it is rubbed over the face of the block,as described, with the firstsolution and allowed to sink in and dry. Adry heat is then applied to the block sufficient to coagulate thealbumen which underlies the gelatine within the pores of the wood.Another coat of the gelatine solution may then be applied, whichgenerally presents a glazed appearance on parts of the surface,indicating that the pores of the wood are completely filled. Any excessof gelatine which appears on the surface must be removed by scrapingwith a knife, or otherwise, and the block is then ready for the silversolution, which is applied in the same manner as to paper, with theexception that sufficient friction must be employed to remove any filmof gelatine which may cover the wood, and to bring the silver solutioninto direct contact with the surface of the wood itself. The printing isthen performed precisely as on paper, excepting that the picture is mademuch darker than it is intended to remain. The solvent or fixing andtoning solution is then applied in a heated state, which, in'addition toits customary effect in photographs upon paper, acts by its heat todissolve and completely remove all the gelatine which has been applied.The pores of the wood are thus freed of everything but the coagulatedalbumen, and all parts of the picture elfaced, excepting such as weretaken directly upon the surface of the wood. It is therefore needful, asbefore stated, that the picture should be originally printed so deeplyas to completely obliterate a large part of its forms, which reappear onthe removal of the gelatine.

The remarkable adaptability of the albumen and gelatine as applied bymeforthe purposes they are designed to subserve may be summed up in afew words. The albumen is first applied to form, when coagulated bydirect heat, an insoluble base within the pores of the wood. Thegelatine is then applied in such quantity as to fill the pores withoutoverspreading the surface of the wood in any part, and, beingreluctantly soluble in cold water, permits the silver solution to becomeincorporated with the substance of the wood, but prevents its unduepenetration. After the printing is completed the warm fixing solutioncompletely removes the gelatinous matter, which would otherwise causeinconvenience in engraving and stereotyping, and leaves the surface ofthe wood in its natural state,precisely as the engraver wants it. Thecoagulated albumen, being free from any viscidproperty, causes noinconvenience to the engraver or stereotyper.

The picture produced by this process is proof against injury fromfriction, and admits of the surface of the block being sponged orwashed,

if necessary, with perfect impunity.

Either the albumen or the gelatine may be used alone with considerablesuccess; but I have found the best results to be produced by theircombined use as above described.

' I am aware that both albumen and gelatine have been employed on woodas filmsor coats on which to take pictures by the photographic process;but I know of no instance in which these substances have been applied asabove described to prevent the undue penetration of the sensitivesolution while the photographic image is taken directly upon the surfaceof the wood itself.

Iclaim therefore as new and of myinvention, and desire to secure byLetters Patent-- I 1. The described or substantially equivalent methodof applying albuminous matter and afterward coagulatingit by heat, so asto form an insoluble base within the pores of the wood, for the purposeset forth.

2. Taking photographic pictures upon wood the pores of which have beenfilled with gelatine or its equivalent and subsequently removing thegelatine from the block without injury to the picture by the applicationof a warm solvent.

In testimony of which I hereunto set my hand.

CHAS. B. BOYLE.

Witnesses:

OOTS KNIGHT, W. Y. ATLEE.

